Not to toot my own horn, but I have some palettes on my site, too. (The link is in my siggy). Sadly, no new tutorials yet. Those will come - and hopefully soon.

The shape of the shirt is actually not bad. And solid colouring is actually, in my opinion, a better start then shading to the base/pillow shading. Sometimes those are hard habits to get out of. *always colour the space in with a solid colour before shading. That keeps you away from those kind of mistakes. ^^